The present work includes design, construction and operates of a prototype solar absorption refrigeration system, using methanol as a refrigerant to avoid any refrigerant that cause global warming and greenhouse effect. Flat plate collector was used because it’s easy, ninexpensive and efficient. Many test runs (more than 50) were carried out on the system from May to October, 2013; the main results were taken between the period of July 15, 2013 to August 15, 2013 to find the maximum C.O.P, cooling, temperature and pressure of the system. The system demonstrates a maximum generator temperature of 93.5 oC, on July 18, 2013 at 2:30 pm, and the average mean generator temperature Tgavr was 74.7 °C, for this period. The maximum pressure Pg

This paper presents the design, construction and investigates an experimental study of a parabolic Trough Solar Collector (PTSC). It is constructed of multi – piece glass mirror to form the parabolic reflector (1.8 m ? 2.8 m) its form were checked with help of a laser and carbon steel rectangular as receiver. Sun tracker has been developed (using two – axis) to track solar PTSC according to the direction of beam propagation of solar radiation. Using synthetic oil as a heat transfer its capability to heat transfer and load high temperature (?400 oc). The storage tank is fabricated with stainless steel of size 50 L. The experimental tests have been carried out in Baghdad climatic conditions (33.3o N, 44.4o E) during selective days of the

Influenza is a highly infectious and lethal viral disease, it appears on Earth periodically in connection with the passage of comet in the vicinity of Earth around the Sun .it is believed that particles spread from the tail of the comet due to solar heating energy ,are contaminated with very tiny small particles considered as viruses. Viruses reach the Earth with the power of the solar wind due to solar activity cycle which is driven every 11 year. Viruses pushed towards Earth’s atmosphere, then precipitate on clouds and reach the surface of Earth. These viruses are very well shielded and unaffected by even UV radiation ,but the only way the shell is melt when they passes through the digestive system . Results showed a good correlation

This research dedicated to make an investigation for the variation of electron density concentration of D- region(NmD), at a characteristic height of 81 km throughout solar cycle 23, with solar activity(represented by sunspot number indices: international sunspot number(Ri), Northern hemisphere sunspot number(Rn) and Southern hemisphere sunspot number(Rs), as well as, the correlation between these indices for Baghdad city(lat.: 33.3o N, long.: 44.4o E) at local noon time during the ascending and the descending phases of solar cycle 23. A very strong directly relationship were found between Ri, Rn and Rs with NmD, as well as, the correlation coefficient between these parameters have been calculated and it has been found it is equal, i.e.,

This paper compare  the accurecy of HF propagation  prediction programs for  HF circuits links between Iraq and  different points world wide  during August 2018 when  solar cycle 24 (start 2009 end 2020) is at minimun activity and also find out the best communication mode  used. The prediction   programs like Voice of America Coverage Analysis Program (VOACAP) and ITU Recommendation RS 533 (REC533 )  had been used to generat HF circuit link  parameters like Maximum Usable Frequency ( MUF) and Frequency of Transsmision (FOT) .Depending  on the predicted parameters (data)  , real radio contacts had been done using a radio transceiver from Icom  model IC 7100 with 100W RF

Design and build a center basins new p-type four mirrors were studied its effect on all parameters evaluating the performance of the solar cell silicon in the absence of a cooling system is switched on and noted that the efficiency of the performance Hzzh cell increased from 11.94 to 21 without cooling either with cooling has increased the efficiency of the

This paper  studied  kinetics  of flotation   of  emulsified  paraffine  in  water  in  bubble  column  with  sodium .dodecylsulphate as a collector agent. The effects of oil drops and air bubble diameters on the flotation rate constant were studied. The removal rate for each oil drop size was first order with respect to oil drop concentration. An experimental procedure permitting determination of the first order rate constants for  removal due to bubble/drop interaction was developed, decreasing bubble diameter by adding NaCl and increasing oil drop diameter increased the rate constants. A comparison between the experimental and theoretical rate constants showed

A paraffin wax and copper foam matrix were used as a thermal energy storage material in the double passes air solar chimney (SC) collector to get ventilation effect through daytime and after sunset. Air SC collector was installed in the south wall of an insulated test room and tested with different working angles (30^o, 45^o and 60^o). Different SC types were used; single pass, double passes flat plate collector and double pass thermal energy storage box collector (TESB). A computational model based on the finite volume method for transient tw dimensional domains was carried out to describe the heat transfer and storage in the thermal energy storage material of collector. Also, equivalent specific heat metho

The design, construction and investigation of experimental study of two compound parabolic concentrators (CPCs) with tubular absorber have been presented. The performance of CPCs have been evaluated by using outdoor experimental measurements including the instantaneous thermal efficiency. The two CPCs are tested instantly by holding them on a common structure. Many tests are conducted in the present work by truncating one of them in three different levels. For each truncation the acceptance half angle (θ_c) was changed. Geometrically, the acceptance half angle for standard CPC is (26^o). For the truncation levels for the other CPC 1, 2 and 3 the acceptance half angle were 20^o, 26^o and 5